Snow tractor



July24, 1951 M, TUCKER 2,551,716

SNOW TRACTOR Filed Jan. 23. 1946 .E'f- W. Tucker ATTORNEYS INVENTORelement Patented July 24, 1951 to Tucker and poration I Sons, GrassValley, Calif., a corpawm ana 23,1946, Serial No. 642,892

- '2 Claims. (01.180

This invention relates to "tractor type vehicles for use in transportingpersons and material over snow covered areas where ordinary vehiculartraflic is impossible. I

The present invention constitutes an improvement over that type of snowtractor shown in my issued PatentNo. 2,341,000. I r

One of the primary essentials in a snow tractor is that there shall beas few movingparts as possible. This is for thereasonthatin travellingthrough the snow, the snow tends to pack into the mechanism and oftenfreezes, and insodoing tends to break any relatively movable ,parts'dueto the strain imposed thereon by the frozen snow. I Inmy previous patentthe endless driving ,tr'ack moved at each end over a pair of movablediscs which were supportedbyithe mainsuriporting pontoon of the vehicleand had movement relativethereto. The present invention contemplates theelimination of these movable discs and the substitution therefor of anew and improved type of supporting pontoon and continuous track elementabout which the endless driving element moves-thus reducing the numberof movable parts and the possibility of breakage.

A further object of the invention is to produce a practical device andone which will be exceedingly effective for the purpose for which it isdesigned.

These objects are accomplished by means of such structure and relativearrangement of parts as will fully appear by a perusal of the followingspecification and claims.

In the drawings:

Figure 1 is a side elevation of my improved snow tractor showing thevehicle body in outline and my improved type of supporting and drivingelement mounted thereon.

Figure 2 is a fragmentary sectional view taken on a line 22 of Fig. 1.

Referring now more particularly to the characters of reference on thedrawings, the numeral I designates generally the vehicle body which inthe present instance is illustrated as being supported at the front endby pivoted ski elements 2 which may be of any form adaptable to thistype of vehicle.

My improved supporting and driving element includes a drive shaft 3suitably mounted in the vehicle body I and which will be connected inany conventional manner with a prime mover such as a gasoline engine orthe like carried in the body I but which, being conventional, is notshown in the drawings.

The numeral 4 designates a supporting frame as shown by Fig. 2.

distance through the slots 5.

or pontoon which is shown in the-d-rawings as being of elongated formand substantially rectangular in cross section. This member 4 ishollowand substantially enclosed on all sides except at the upper sidewherein is provided a pair ofzslots 5 for a purpose which will presentlyTheshaft 3 projects through the pontoon 4 at a point therein and issuitably journaled in the side walls of saidpontoon in any desiredmanner Suitably fixed to said shaft is a d vi disc or hub (i on whichare one or more sprocket wheels 1 which project a short Formed about orattached to thesides of the pontoon 4 adjacent the peripheral edgethereof are continuous and endless channel tracks 8.

The endless driving traction element 9," which may be made up in anyform of linked-together ground engaging elements, is provided on itsinner side with a plurality of rollers I0. These rollers I0 engage andtravel the endless tracks 8.

In the present instance the element 9 includes a plurality of cross barsH which are linkedtogether and are supported by the links and rollersIll. The endless element 9 is driven about the pontoon through theaction of the sprockets I which engage these bars I I and with therotation of the drive shaft 3, drive the element 9 about the pontoon 4,which in turn imparts motion to the vehicle body I.

It will be seen that the element. 4 with the tracks 8 forms a unitaryand rigid support for the endless driving member 9 with no relativelymovable parts therein as shown in the previous patent in which rotatablediscs were mounted at the end of the supporting pontoon and about whichthe endless element moves. In the former type of mechanism the element 9could be adjusted to its proper taut position by adjustment of thediscs. With such a unitary and solid structure as presented by thepontoon 4 and the tracks 8 in the present application, such a type ofadjustment for the endless element 9 is not possible. However, I haveprovided for this contingency and may effect a tightening of the element9 through the medium of a chain tightener I2 which element 9 and thusshorten the over-all length of such element in a manner taught by mypending application for patent, filed July 2, No. 602,806, nowabandoned, in which an element like that shown by the numeral I2 isshown and described in detail and its manner of use fully illustrated.

may be used to bend the links of the I 1945, Serial edge thereof, suchFrom the foregoing description it will be apparent that I have}materially simplified and improved the supporting and driving element ofmy previous patent and eliminated many moving parts and minimizedthechances of breakage of the operating parts ,of the tractor.

While this specification sets forth in detail the presentand preferredconstruction of the device, still in'practice such deviations from suchdetail may be resorted to as do not form a departure from the spirit ofthe invention, as defined by the appended claims. I

Having thus described the invention, the following is claimed. as newand useful and upon which Letters Patent is desired:

1. A snow tractor including a vehicle body, a and driving means for saidbody, such;

means includin a drivin shaft mounted on such);

g g .erable over the trackway in such channel, a

supporting body, a supportingpontoon, such pontoon being enclosed on allsides except at a point adjacent *thetop thereof where it is providedwith a longitudinal slot, the outer end of the shaft being journaled inthe sidesof said pontoon, a continuous and endless track disposed aboutand being rigid with each side of the pontoon adjacent the peripheraledge thereof, an endless driven element comprising ground engaging crossbars spanningthe outer periphery of the pontoon from edge to" bars beinglinked together at their outer ends at both sides of the pontoon,"

rollers journaled on each set of the links and supported byand operableover one of the tracks, a sprocket wheel on the shaft within thepontoon, the teeth of such sprocket wheel projecting through said slotand engageable with the bars spanning the periphery of the pontoon.

2. A snow tractor including a vehicle body, a

, supporting and driving means for said body, such means comprising adriving shaft 's'uch body, a supporting pontoon, such pontoon mounted onbeing enclosed on all sides except at a point adjacent the'top thereofat which point it is provided with a longitudinal slot, the outer end ofthe shaft being journaled in the sides of the pontoon, each side of thepontoon being formed with a continuous, endless channel adjacent theperipheral edge thereof, the inner side of each channel providing anendless continuous trackway, an endless driven element comprising groundengaging cross bars spanning the outer periphery of the pontoon fromedge to edge thereof, such bars being linked together at their outerends at both sides of the pontoon, rollers journaled on each set of thelinks and projecting into the adjacent channel and being supported byand opsprocketwheel on the shaft within the pontoon,

the teeth of such wheel projecting through said slot and beingengageable with. the bars spanning the outer periphery of the pontoon.

EMMITT M. TUCKER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

